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Chiral overcrowded alkenes; Asymmetric synthesis of (3S,3′S)‐(M,M)‐(E)‐(+)‐1,1′,2,2′,3,3′,4,4′‐octahydro‐3,3′,7,7′‐tetramethyl‐4,4′‐biphenanthrylidenes
Author(s) -
Ter Wiel Matthijs K.J.,
Koumura Nagatoshi,
Van Delden Richard A.,
Meetsma Auke,
Harada Nobuyuki,
Feringa Ben L.
Publication year - 2000
Publication title -
chirality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.43
H-Index - 77
eISSN - 1520-636X
pISSN - 0899-0042
DOI - 10.1002/1520-636x(2000)12:10<734::aid-chir6>3.0.co;2-q
Subject(s) - chemistry , chirality (physics) , ketone , stereochemistry , alkylation , enantioselective synthesis , absolute configuration , catalysis , organic chemistry , physics , chiral symmetry breaking , quantum mechanics , nambu–jona lasinio model , quark
An asymmetric synthesis route towards (3S,3′S)‐(M,M)‐(E)‐(+)‐1,1′,2,2′,3,3′,4,4′‐octahydro‐3,3′,7,7′‐tetramethyl‐4,4′‐biphenanthrylidene was developed using the Evans procedure as a key step. The absolute configurations of the title compound and of its parent ketone were determined by CD spectroscopy and could be correlated with the stereochemical results of the asymmetric alkylation. Furthermore, a comparison was made with the known (3R,3′R)‐(P,P)‐(E)‐(–)‐1,1′,2,2′,3,3′,4,4′‐octahydro‐3,3′,7,7′‐dimethyl‐4,4′‐biphenanthrylidene. Finally, the X‐ray crystallographic analysis of (3S,3′S)‐(M,M)‐(E)‐(+)‐1,1′,2,2′,3,3′,4,4′‐octahydro‐3,3′,7,7′‐tetramethyl‐4,4′‐biphenanthrylidene is presented. Chirality 12:734–741, 2000. © 2000 Wiley‐Liss, Inc.